Elections via Blockchain, fact or fiction?

Let's analyze the use that is made of Blockchain technology in the Electoral world; sometimes rightly, sometimes not.

Let's start by understanding what a Blockchain is. A Blockchain is what in computer terms is called a distributed immutable log. This is a Ledger, a Record, a Log file in which users and services can write, and what is written reaches an indeterminate number of receivers (nodes) simultaneously that protect the written data cryptographically so that it cannot be modified or deleted.

If you want a deeper explanation on blockchain click this link: https://blockgeeks.com/guides/what-is-blockchain-technology/

These immutability and concurrent reception properties across multiple nodes allows creating exciting new business models. For example, cryptocurrencies use this property to conduct secure monetary transactions without any bank monitoring or managing them. The Blockchain cryptocurrency community self-manages.  

Let's see how these properties apply to Electoral Processes.

When we talk about Electoral Processes we all thing about the act of introducing a ballot in the ballot box to be part of the count executed at the end of polling day.

Thinking on Blockchain terms, the first idea that comes to mind is to implement an electronic vote over the Internet that saves the votes in the Blockchain. This ensures that votes are immutable and received by multiple recipients simultaneously. The proponents of this technique can argue that it increases transparency. However, the problem is that in an Electoral Process more properties must be guaranteed during voting: non-repudiation, privacy, the integrity of the ballot box, the opportunity to vote  (the voting system's ability to process the votes of all voters who want to vote during the time the voting process is open),among others.

Let's look at these properties in more detail.

Integrity:  We have already seen that Blockchain guarantees the integrity of the ballot box, but it does so at the cost of using cryptographic processes that are very intensive and slow, and that increase its cost in an accelerated way with each node  (each of the receivers)  that is added to the Blockchain. Thus, to ensure that a few million people can vote in a single day on a Blockchain-based ballot box, a very high-cost computing infrastructure would be needed. The cost increases with the number of nodes, as does the perception of transparency; and performance drops as the number of nodes increases, thus reducing the opportunity to vote.

To prevent unassumable computing costs, the number of Blockchain nodes should be limited and this limits the number of citizens who can perform checks, reducing the perception of transparency.

Privacy:  If an undetermined number of recipients receive copies of the votes, even if they are encrypted, the risk of attacks to the cryptographic protection of the vote encryption increases, thereby putting the voter's privacy at risk.

Some systems propose to keep votes in the Blockchain unencrypted. This situation is equivalent to free-hand voting in a room and should not even be considered for secret voting election processes.

Non Repudiation:  This is the property that ensures that a voter cannot reject the vote he or she cast. At the time of recount, and assuming that the votes are encrypted, two situations can occur.

1. In the first situation, the key to deciphering votes is published to have full transparency so that everyone can count. This publication of the decryption key converts de facto the secret vote into a freehand vote. It opens the door to all kinds of coercion and vote selling, and also destroys the protection against non-repudiation.

Let's take an example. In an election in which the result has been close, the decryption key is published and several voters who when deciphering see that their vote is for candidate A complain and say they voted for candidate B. This situation calls into question the integrity of the voting process and the legitimacy of the result. Did the voter vote for the wrong candidate by mistake? Does the voter not remember who he or she voted for? Did the voter vote for A  on purpose to complain after the results were published?

Electoral Processes need the recount to be Final, Secret, and Legitimate. Thus, publishing the decryption key is not a good practice.

1. Alternatively, the decryption key is held protected by custodians so that none of them can use it without having the other custodians. The key is rebuilt with the collaboration of the custodians only for the time necessary to process the encrypted votes and give the result, and then it is destroyed again.

Oh! But what about transparency?

At this point, the following can be said. It is not appropriate to use a Blockchain as ballot box to store votes in an Electoral Process.

The properties of the Blockchain of immutability and simultaneous reception of information are very interesting in an Electoral Process. But its use should be that of the General Ledger, not the one of Ballot Box.

A multitude of tasks are carried out in an Electoral Process. For example, and without being exhaustive, it is verified which citizens have the right to vote; districts are designed and voters are assigned to polling places and polling stations; nominations are processed, accepted or rejected; ballots are designed; poll workers are assigned to the polling station; communications of polling station opening, incidents, participation, polling station closure and polling station results are made.

All these processes must be included in the General Ledger, and if we use Blockchain technology we bring a level of transparency and integrity to the process very difficult to overcome.

If we return to the online voting scenario, the use of Blockchain is then appropriate to give transparency to the entire process of setting up the voting process. It is also appropriate to store a digital signature of encrypted votes in the Blockchain, to ensure that the ballot box where the encrypted votes are stored does not suffer attacks of erasure or alteration of votes.

But the transparency and correct decryption of the votes in this case shall not be provided by the Blockchain but rather by the use of homomorphic cryptography of elliptical curves. This is a very interesting topic that we will address in a future article.

Inshort: blockchain technology provides great possibilities to increase transparency in Electoral Processes, but inappropriate use can introduce new problems.